Department of Horticulture, Rajasthan Agricultural Research Institute (Sri Karan Narendra Agriculture University, Jobner) Durgapura, Jaipur, Rajasthan, 302018 IndiaIndia
Department of Plant Pathology, Rajasthan Agricultural Research Institute (Sri Karan Narendra Agriculture University, Jobner), Durgapura, Jaipur, Rajasthan, 302018 IndiaIndia
Department of Plant Physiology, Rajasthan Agricultural Research Institute (Sri Karan Narendra Agriculture University, Jobner), Durgapura, Jaipur, Rajasthan, 302018 IndiaIndia
Department of Plant Breeding & Genetics, Rajasthan Agricultural Research Institute (Sri Karan Narendra Agriculture University, Jobner), Durgapura, Jaipur, Rajasthan, 302018 IndiaIndia
Department of Plant Physiology, SKN College of Agriculture, SKN Agriculture University, Jobner, Rajasthan, 303329 IndiaIndia
Department of Plant Pathology, Rajasthan College of Agriculture, MPUAT, Udaipur, Rajasthan, 313001 IndiaIndia
Department of Horticulture, SKN College of Agriculture, SKN Agriculture University, Jobner, Rajasthan, 303329 IndiaIndia
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Seed priming and foliar application of amino acids offer a sustainable route to improve seed performance and early seedling vigour in vegetable nurseries. This study evaluated arginine (Ag) for enhancing seed germination and early seedling growth in Capsicum (Capsicum annuum L. cv. Indra). Seeds were treated for 60 min with Ag at 25–300 ppm and compared with water (control) in a randomised pro-tray experiment conducted in a naturally ventilated polyhouse over two seasons (2024–25 and 2025–26). Germination, germination energy, shoot and root length, seedling fresh and dry weight, total chlorophyll and seedling vigour indices were recorded. All Ag concentrations improved germination and seedling traits over the control, and the 200 ppm treatment performed best: germination reached 98.16 % (control 81.00 %), germination energy increased 5.9-fold, shoot and root length by 1.92- and 1.94-fold, seedling fresh and dry weight by 2.06- and 1.61-fold, total chlorophyll by 1.63-fold, and seedling vigour indices I and II by 2.34- and 1.90-fold, respectively. At 100–300 ppm, Ag also gave significantly higher germination, germination energy and vigour indices than arginine at 25 ppm. Responses declined at 250–300 ppm, indicating a concentration optimum. Seed priming and foliar application with 200 ppm Ag is therefore a promising, eco-friendly approach for producing vigorous Capsicum seedlings.
Keywords: Arginine; Seed priming; Capsicum annuum; Seedling vigour; Sustainable horticulture; Seedpriming; Capsicumannuum; Seedlingvigour; Sustainablehorticulture
1.Introduction conductedduringthekharifseasonsof2024–25and 2025–26inanaturallyventilatedpolyhouseusingCap- Capsicum(CapsicumannuumL.),commonlyknown sicumcv.Indra.Laboratoryanalyseswereperformed asbellpepper,belongstothefamilySolanaceae. Its intheDepartmentofHorticulture,SKNCollegeofAgri- fruitsareavaluablesourceofvitaminC(150–180mg culture,Jobner.
per100g),vitaminA,potassium,phosphorus,magne- siumandcalcium[1,2],andtheirbioactiveconstituents 2.2 SeedlingBioassay havebeenassociatedwithprotectiveeffectsagainst SeedsofCapsicumannuumL.cv.Indraweretreated cardiovasculardisorders,cancerandhypercholestero- for60minwithoneofeighttreatments: water(con- laemia[3].GlobalacreageandproductionofCapsicum trol)andAgat25,50,100,150,200,250and300ppm areestimatedat1.99millionhectares(Mha)and38.02 (w/v).Followingtreatment,theseedsweresun-dried milliontonnes(Mt),respectively,withChinaandMex- andsowninpro-trayscontainingcocopeat,perliteand icoastheleadingproducers[4];inIndiathecropoc- vermiculiteina3:1:1ratiounderpolyhouseconditions. cupiesabout0.042Mhawithaproductionof0.66Mt Inadditiontoseedtreatment,twofoliarapplications [5].Raisinghealthy,uniformseedlingsisthefirststep oftherespectiveAgtreatmentswereappliedat15and towardsaproductiveCapsicumcrop.Primingandfo- 25daysaftersowing(DAS).Theexperimentfollowed liarapplicationaresimple,low-costtechniquesthat arandomizedblockdesign(RBD)withthreereplica- hastengermination,improveuniformityandpromote tions,with100seedspertreatmentineachreplication vigorousseedlinggrowthinvegetablecrops[6,7]. (300seedspertreatment),andwasrepeatedintwosuc- Conventionalcrop-inputstrategiesrelyoninorganic cessiveseasonsfollowingstandardseed-testingproce- fertilizersandagrochemicals[8],whoseindiscriminate dures[18].
use raises concerns about residues, human health andenvironmentalsafety[9].Attentionhastherefore 2.3 Observations turnedtobio-basedseedprimingandfoliarapplica- Germinationwascountedat5-dayintervalsupto30 tion have been shown to improve seed vigour and daysaftersowing(DAS).Germination(%)at30DAS early seedling establishment [10,11]. Amino acids wascalculatedas(germinatedseeds/totalseedssown) are the building blocks of proteins and influence × 100.Meandailygermination(MDG)wascalculated cellular processes such as growth, stress resistance asgermination(%)dividedbythetotalnumberofex- and metabolism [12], which makes them attractive perimentaldays(30)[19],andgerminationenergy(GE) activeingredientsforsuchformulations. asthepercentageofseedsgerminatedbythe15thday Arginine, inparticular, isanitrogen-richaminoacid [20].Growthparameterswererecordedat30DASon thatservesasamajornitrogenreserveandasapre- 10seedlingsperreplicate.Shootandrootlengthswere cursor of polyamines and nitric oxide [13,14]. Seed measuredwithascale(cm),andrelativerootelonga- primingwithargininehasbeenreportedtoimprove tion(RRE,%)wascalculatedas(meanrootlengthof germinationorgrowthinpepperandwheat[14–16], treatedseedlings/meanrootlengthofcontrol) × 100 andfoliararginineimprovedtomatogrowth,yieldand [20].
fruitquality[17].Toourknowledge,however,arginine Freshweightwasrecordedonaprecisionbalance(Saf- hasnotbeenevaluatedasaseedprimingandasafoliar fronSES200)afterwashingtherootsfreeofmedium, applicationinCapsicum.Thepresentstudytherefore anddryweightaftershade-dryingtoconstantweight. aimedtoevaluatearangeofconcentrations(25–300 Totalchlorophyllwasdeterminedbythedimethylsul- ppm)ofanarginine(Ag)againstcontrol(water)foref- foxide(DMSO)method[21]: 50mgofleaftissuewas fectsonseedgermination,seedlinggrowth,biomass, ◦ incubatedin5mLDMSOat65 Cfor4hinthedark, chlorophyllcontentandseedlingvigourofCapsicum absorbancewasreadat663,645and480nmagainst inapro-traybioassayovertwoseasons.
a DMSO blank, and chlorophyll a and b were calcu- lated from A663 and A645, summed and expressed 2.MaterialsandMethods −1 asmgg freshweight(FW).Seedlingvigourindices 2.1 ExperimentalSiteandPlantMaterial werecalculatedasSVI-I=germination(%) × seedling TheinvestigationwascarriedoutattheDepartmentof length(shoot+root,cm)andSVI-II=germination(%) Horticulture,RajasthanAgriculturalResearchInstitute × seedlingdryweight(mg)[22].
(Sri Karan Narendra Agriculture University, Jobner), ◦ ′ ◦ ′ Durgapura,Jaipur,Rajasthan,India(26 51 N,75 47 2.4 StatisticalAnalysis E;390mabovemeansealevel;agro-climaticzoneIII-a, DatawereanalysedusingJMPversion18[23]andtreat- semi-arideasternplain). Seedlingexperimentswere mentmeanswereseparatedbytheTukey–Kramerhon- Capsicumat30DAS.
Treatment Germination(%) MDG GE(%) Control(water) 81.00 ± 0.78f 2.69 ± 0.017e 3.99 ± 0.88f Ag(ppm) 25 86.83 ± 0.77e 2.89 ± 0.017d 10.66 ± 0.72e 50 90.66 ± 0.72d 3.02 ± 0.020c 13.83 ± 0.88d 100 93.49 ± 0.88bc 3.11 ± 0.025bc 16.49 ± 0.49c 150 92.50 ± 0.57c 3.08 ± 0.008bc 17.00 ± 0.57c 200 98.16 ± 0.45a 3.26 ± 0.008a 23.66 ± 0.72a 250 94.50 ± 0.57b 3.14 ± 0.011b 20.50 ± 0.57b 300 91.99 ± 0.60cd 3.06 ± 0.034bc 17.49 ± 0.88c Valuesaretwo-seasonmeans ± SEofthreereplicatesof100seeds.Meansfollowedbythesameletterwithinacolumndonotdiffer significantly(Tukey–KramerHSD,p=0.05).
Treatment Germination(%) MDG GE(%) Control(water) 81.00 ± 0.78f 2.69 ± 0.017e 3.99 ± 0.88f Ag(ppm) 25 86.83 ± 0.77e 2.89 ± 0.017d 10.66 ± 0.72e 50 90.66 ± 0.72d 3.02 ± 0.020c 13.83 ± 0.88d 100 93.49 ± 0.88bc 3.11 ± 0.025bc 16.49 ± 0.49c 150 92.50 ± 0.57c 3.08 ± 0.008bc 17.00 ± 0.57c 200 98.16 ± 0.45a 3.26 ± 0.008a 23.66 ± 0.72a 250 94.50 ± 0.57b 3.14 ± 0.011b 20.50 ± 0.57b 300 91.99 ± 0.60cd 3.06 ± 0.034bc 17.49 ± 0.88c Valuesaretwo-seasonmeans ± SEofthreereplicatesof100seeds.Meansfollowedbythesameletterwithinacolumndonotdiffer significantly(Tukey–KramerHSD,p=0.05). estlysignificantdifference(HSD)testatp=0.05.Values 23.66%versus3.99%)followedthesamepattern.Ag arepresentedasmeans ± standarderror(SE)ofthe at200ppmgavethehighestvaluesforallthree(98.16 twoseasons.
%,3.26and23.66%),a1.21-foldincreaseingermina- tionanda5.9-foldincreaseingerminationenergyover thecontrol.
3.Results 3.1 SeedGermination 3.2 ShootandRootGrowth Nogerminationoccurredat5DASinanytreatment, Shootlengthincreasedfrom6.4cminthecontrolto andgerminationbeganat10DAS(Table1).Ateveryob- 7.7–12.3cmacrossAgconcentrations,androotlength servation,allAgconcentrationsrecordedsignificantly from8.7to11.2–16.9cm(Table3). At150–250ppm moregerminatedseedsthanthecontrol. At10DAS, bothtraitsweresignificantlygreaterthanwithcontrol, Aggave5.83–12.83germinatedseedsper100against withthemaximumat200ppm(shoot12.3cm,1.92- 1.16inthecontrol.The200ppmtreatmentledatevery fold;root16.9cm,1.94-foldoverthecontrol).Relative stage,with12.83,23.66,93.83and98.16seedsper100 rootelongationreached193%at200ppmandranged at10,15,20and30DAS,respectively,comparedwith from150to193%at150–300ppm,against100%with 1.16,3.99,70.16and81.00inthecontrol. control.
Finalgerminationat30DASrangedfrom86.83to98.16 %acrossAgconcentrations,against81.00%inthecon- 3.3 BiomassandChlorophyllContent trol(Table2).Meandailygermination(2.89–3.26ver- Seedlingfreshweightwashighestat200and250ppm sus2.69inthecontrol)andgerminationenergy(10.66– (0.817and0.793g),abouttwicethecontrol(0.396g) seedlingsat30DAS.
−1 Treatment Freshweight(g) Dryweight(g) Totalchlorophyll(mgg FW) Control(water) 0.396 ± 0.014f 0.061 ± 0.001e 1.36 ± 0.011f Ag 25 0.564 ± 0.014cde 0.082 ± 0.001cd 1.78 ± 0.016e 50 0.556 ± 0.012cde 0.084 ± 0.001bcd 1.87 ± 0.013cd 100 0.643 ± 0.015cd 0.086 ± 0.002bc 1.90 ± 0.012cd 150 0.675 ± 0.016bc 0.091 ± 0.002ab 1.95 ± 0.011c 200 0.817 ± 0.016a 0.098 ± 0.001a 2.21 ± 0.012a 250 0.793 ± 0.017ab 0.095 ± 0.002a 2.10 ± 0.012b 300 0.658 ± 0.017cd 0.087 ± 0.001bc 1.89 ± 0.015cd Valuesaretwo-seasonmeans ± SEofthreereplicatesof10seedlings.Meansfollowedbythesameletterwithinacolumndonotdiffer significantly(Tukey–KramerHSD,p=0.05).FW,freshweight.
Treatment Freshweight(g) Dryweight(g) Totalchlorophyll(mgg FW) Control(water) 0.396 ± 0.014f 0.061 ± 0.001e 1.36 ± 0.011f Ag 25 0.564 ± 0.014cde 0.082 ± 0.001cd 1.78 ± 0.016e 50 0.556 ± 0.012cde 0.084 ± 0.001bcd 1.87 ± 0.013cd 100 0.643 ± 0.015cd 0.086 ± 0.002bc 1.90 ± 0.012cd 150 0.675 ± 0.016bc 0.091 ± 0.002ab 1.95 ± 0.011c 200 0.817 ± 0.016a 0.098 ± 0.001a 2.21 ± 0.012a 250 0.793 ± 0.017ab 0.095 ± 0.002a 2.10 ± 0.012b 300 0.658 ± 0.017cd 0.087 ± 0.001bc 1.89 ± 0.015cd Valuesaretwo-seasonmeans ± SEofthreereplicatesof10seedlings.Meansfollowedbythesameletterwithinacolumndonotdiffer significantly(Tukey–KramerHSD,p=0.05).FW,freshweight. (Table 4). Dry weight followed a similar trend, with 4.Discussion 150–250ppmgiving0.091–0.098gagainst0.061gin 4.1 SeedPrimingResponseandDoseDependence thecontrol.Totalchlorophyllwassignificantlyhigher SeedprimingandfoliarapplicationofAgaccelerated thanthecontrolinallAgtreatments(1.78–2.21versus −1 −1 and improved germination and enhanced seedling 1.36mgg FW),peakingat200ppm(2.21mgg FW; growth, biomass, chlorophyll content and vigour in 1.63-foldoverthecontrol).
Capsicum, with the strongest effects at 200 ppm in both seasons. Germination is a decisive stage for cropestablishment,andprimingimprovesthespeed 3.4 SeedlingVigourIndices and uniformity of germination through controlled SVI-Iincreasedfrom1227inthecontrolto1649–2870 hydration and early metabolic activation [6,7]. The withAg,andSVI-IIfrom5085to7163–9669(Table5). improvement observed here is in line with reports Bothindicesweremaximalat200ppm(2.34-and1.90- that seed priming and foliar application enhance foldoverthecontrol),andeveryAgtreatmenthada seedvigourandearlyseedlingestablishment[10,11]. significantlyhigherSVI-IIthancontrol;SVI-Iwassignifi- Theresponsewasconcentrationdependent: values cantlyhigherthanwithcontrolat100–300ppm.Vigour rose up to 200 ppm and declined at 250 and 300 declinedat250and300ppmbutremainedabovethe ppm, although they stayed above the untreated control.The200ppmtreatmentrecordedthehighest control. For fresh and dry weight, 250 ppm did not valueforeverytraitinbothseasons.
differ significantly from 200 ppm (Table 4), so the biomass optimum spans 200–250 ppm, whereas Treatment SVI-I SVI-II Control(water) 1227 ± 47.3g 5085 ± 20.1g Ag(ppm) 25 1649 ± 36.8ef 7163 ± 28.2f 50 1717 ± 27.3e 7662 ± 21.3e 100 1940 ± 28.5d 8088 ± 23.6d 150 2054 ± 32.8c 8371 ± 23.6c 200 2870 ± 21.3a 9669 ± 23.6a 250 2438 ± 21.9b 8977 ± 15.8b 300 2050 ± 29.1cd 8048 ± 26.5d SVI-I=germination(%) × seedlinglength(cm);SVI-II=germination(%) × seedlingdryweight(mg).Valuesaretwo-seasonmeans ± SE. Meansfollowedbythesameletterwithinacolumndonotdiffersignificantly(Tukey–KramerHSD,p=0.05). germination, growth and vigour peaked sharply at couldexplainthegreaterefficacyoftheformulation; 200ppm.Optimum-typeresponsesofthiskindhave however,uptakeandreleasewerenotmeasuredhere, beennotedforseedprimingandunderlinetheneed sothisexplanationremainstobetested.
4.3 PracticalImplicationsandLimitations 4.2 RoleofArginine Treatingseedswith200ppmAgfor60minraisedgermi- nationabove98%andproducedmarkedlymorevigor- Arginineisamajornitrogenreserveinplants:itshigh ous,chlorophyll-richseedlingsinpro-trays,whichisdi- nitrogen-to-carbonratiomakesitareadilymobilizable rectlyrelevanttonurseryproductionofCapsicum.The sourceofnitrogenforthegrowingembryo,anditisa studyislimitedtoonecultivar,onegrowingmedium precursorofpolyaminesandnitricoxide,whichtake anda30-dayobservationwindow,andtheproposed partinhormonalandredoxsignalling[13,14].Exoge- mechanismsareinferredfromtheliteratureratherthan nousargininehasbeenreportedtopromoteseeden- measureddirectly.Furtherworkshouldexaminetrans- ergymetabolismandgerminationinwheat[14],and plantestablishmentandyield,othercultivarsandme- ithasimprovedthegrowthandphysiologicalperfor- dia,uptakeandreleaseofarginine,enzymaticandhor- manceofwheat,maizeandfenugreek,mainlyunder monalresponses,andenvironmentalsafety. waterdeficit[16,24,25].Thefastergermination,greater germinationenergyandhigherchlorophyllcontentof Agtreatedseedlingsareconsistentwiththeseroles,al- 5.Conclusion thougharginineuptake,nitrogenstatusandsignalling Seedprimingandfoliarapplicationwiththearginine werenotmeasuredinthisstudy.
(Ag)significantlyimprovedseedgerminationandearly seedlinggrowthofCapsicumovertwoseasons.Allcon- Arginine at 25 ppm improved germination (86.83 centrationsfrom25to300ppmimprovedgermination, versus 81.00 % in the control) and seedling vigour growth,biomass,chlorophyllcontentandvigourcom- (SVI-II7163versus5085),inagreementwithreported paredwiththeuntreatedcontrol,and200ppmwas benefitsofargininepriminginpepper[15].However, the optimum, giving 98.16 % germination and 2.34- Agat100–300ppmgavesignificantlyhighergermina- and 1.90-fold higher SVI-I and SVI-II. Ag at 100–300 tion,germinationenergyandbothvigourindicesthan ppmalsooutperformed25ppmarginineforgermina- control,andat200ppmitproduced1.13-foldhigher tionandvigour.Agseedprimingisthereforeapromis- germination, 2.2-fold higher germination energy, ingbio-basedoptionforproducingvigorousCapsicum 1.58-and1.51-foldlongershootsandroots,1.45-fold seedlings,anditseffectsontransplantestablishment, higher fresh weight, 1.24-fold higher chlorophyll yieldandthemechanismsinvolvedmeritfurtherstudy. and1.35-foldhigherSVI-IIthan25ppmarginine. At 50 ppm, in contrast, Ag did not differ significantly Citethisarticle: from 25 ppm arginine for shoot length, root length, SagarSaini,UadalSingh,K.K.Meena,RajeshKumar fresh weight or dry weight, so the advantage of the Bagri, Sunita Gupta, S. S. Punia, N. K. Gupta, Akash formulationemergedmainlyathigherconcentrations. Saini,AmanKumarMeena,MadhuBaiMeena,Rahul Seed priming have been proposed to improve the KumarBochalyaandMahendraMeena(2026).Modu- delivery of active molecules to the seed [10], which lationofSeedGermination,SeedlingVigourandEarly GrowthofCapsicumannuumL.SeedlingsbyArginine [11] Sonawane H, Arya S, Math S, Shelke D. Myco- Seed Priming and Foliar Application. Public Health synthesized silver and titanium oxide nanopar- OpenJournal.11(1):811–821.10.17140/PHOJ-11-811 ticles as seed priming agents to promote seed germinationandseedlinggrowthofSolanumly- copersicum:Acomparativestudy. International